基于系统非线性特性的车辆动力总成激振力幅值识别方法研究

Powertrain excitation forces are one of the most important factors that cause vibration and noise in vehicle. The amplitude of forces are difficult to measure directly. In a traditional method to identify the excitation forces of a powertrain, the powertrain mounting system (PMS) is always treated as linear vibration system, the input parameters include the measured amplitude and phase of each mount accelerations. In this project, the modeling, parameters fitting and experimental method for nonlinear dynamic characteristics of the mount are studied. Considering the mutual excitation between each mount, the generation mechanism, calculation and cancellation method of the vibration signal crosstalk in the multi input system are proposed. Take the powertrain excitation forces as the object of study, based on the complex excitation conditions, a new identification method is developed without using the phase information. The identification results are verified through comparing the mount deformation calculation results and test results. The identification method proposed in this project can reduce the influence of system dynamic model error and input parameter error on identification results efficiently. The target of this project is to present an analysis method for complex vibration system in engineering.

动力总成激振力是引起车内振动、噪声的重要因素，直接测量其幅值大小较困难。传统的动力总成激振力识别方法是将动力总成及其支撑悬置组成的动力总成悬置系统视为线性系统，采用测试的悬置振动加速度幅值、相位进行计算。本课题拟研究悬置非线性动态特性的建模、参数拟合及实验分析方法；考虑悬置间的相互激励，提出多输入系统中振动信号串扰成分的产生机理、计算及消除方法；以动力总成激振力为研究对象，基于复杂载荷工况下系统的非线性振动特性，建立不以加速度相位为识别输入参数的动力总成激振力识别计算方法，并验证、分析识别结果。该方法降低了系统模型、输入参数误差等因素对识别结果的影响。项目以提出系统非线性振动动力学分析方法，解决工程中复杂动力学问题为最终目标。

动力总成激振力是引起车内振动、噪声的重要因素，合理的设计动力总成悬置动态特性能够直接衰减由动力总成传递至车内的振动。项目针对动力总成悬置及悬置系统的动态特性仿真、设计方法及动力总成激励识别方法开展了深入的研究。项目的主要成果有：（1）提出了基于卡尔曼滤波的动力总成激励识别方法，分析了识别方法的稳健性；（2）将悬置刚度考虑为三种类型的不确定参数，分别提出了含各类型不确定参数的动力总成激励识别方法；（3）基于Volterra级数法，建立了惯性通道-活动解耦盘式液阻悬置立方非线性阻尼参数的识别方法；（4）建立了立方非线性刚度动力吸振器刚度和阻尼参数的设计方法。项目中提出的系统非线性动态特性分析方法和反问题识别方法，有助于解决工程中的复杂动力学问题。